A team of scientists at the University of Alberta has discovered a completely new way of generating electricity, using nothing more than water flowing over an array of microchannels. On a small scale, this method could produce enough energy to power handheld electronic devices, such as cell phones. On a much larger scale, it has the potential to provide enough electricity to merit adding it as a source to any country's power grid. This was reported in a story by John von Radowitz, a science correspondent for The Press Association.
The electricity production is a result of the natural "electrokinetic" effect of a fluid passing over a solid surface. Where the fluid touches the surface, a minute electrical charge is generated within the thin layer of fluid. This region is referred to as the Electric Double Layer (EDL). The researchers in Alberta discovered that by forcing water through a channel with a diameter approximately the same as the EDL, a small amount of electricity is generated. Admittedly, the energy created is quite small, but because of the tiny diameters involved, the amount of energy can be multiplied by as many microchannels as can be embedded within what is known as an "array".
Professor Larry Kostiuk, a thermodynamicist at the university, and Professor Daniel Kwok, a nanofabrication researcher, combined their knowledge and fields of specialty to come up with the novel concept, and then tested it by passing water through a porous glass filter. Their experiment created enough electricity to illuminate a light bulb, and to prove the validity of their idea. Specifically, they utilized a 30 cm column of water to generate a current of between one and two microamps. Their results were published in the Journal of Micromechanics and Microengineering.
But how does this energy source compare with other clean sources, such as solar and wind? Professor Kostiuk noted that "This discovery has a huge number of possible applications. It could be a new alternative energy source to rival wind and solar power, although this would need huge bodies of water to work on a commercial scale." In the near term, "This technology could provide a new power source for devices such as mobile phones or calculators which could be charged up by pumping water to high pressure."
Dr. David Lynch, the Dean of the Faculty of Engineering at the university, pointed out that, "The discovery of an entirely new way of producing power is an incredible fundamental research breakthrough that occurs once in a lifetime." In this case, the breakthrough is the first new method of electricity generation discovered in 160 years.
In 1800, Alessandro Volta discovered the original electrochemical effect, which is now used in batteries. Twenty one years later, Thomas Seebeck demonstrated that current can be generated from two adjoining metals with differing temperatures. This so-called "Seebeck Effect" is presently the basis of thermoelectric generators. In 1831, Michael Faraday demonstrated that electricity can be created through electromagnetic induction. Eight years after that, Edmond Becquerel discovered the photovoltaic effect, now utilized in solar cells. During that same year, Sir William Grove demonstrated the technology currently used in the fuel cell, which could prove a rival of this new electrokinetic method, for helping to meet future energy demands.